Define a full-text search index using raw SQL concatenation

export const post_schema = pgTable(
    'posts',
    {
        id: serial('id').primaryKey(),
        slug: text('slug').notNull(),
        heading: text('heading').notNull(),
        subheading: text('subheading').notNull(),
        image: text('image').notNull(),
        caption: text('caption').notNull(),
        author_id: integer('author_id'),
        tags: text('tags').array().notNull(),
        article_html: text('article_html').notNull(),
        article_text: text('article_text').notNull(),
        published: boolean('published').default(false).notNull(),
        date_published: timestamp('date_published'),
        updated_by: text('updated_by').notNull(),
        created_at: timestamp('created_at').defaultNow().notNull(),
        updated_at: timestamp('updated_at').$onUpdate(() => new Date())
    },
    (table) => [
        index('posts_search_index').using(
            'gin',
            sql`to_tsvector('english', coalesce(${table.article_text}, ''))`
        )
    ]
);

(table) => [
    index('posts_search_index')
      .using(
        'gin',
        sql`to_tsvector('english', coalesce(${table.heading}, '')) ||
            to_tsvector('english', coalesce(${table.subheading}, '')) ||
            to_tsvector('english', coalesce(${table.article_text}, '')) ||
            to_tsvector('english', array_to_string(${table.tags}, ' '))`
      ),
  ]